1. Field
The present general inventive concept relates to a light emitting diode array integrated with a lens, a line printer head using the light emitting diode array, and a method of manufacturing the light emitting diode array.
2. Description of the Related Art
Light emitting diodes are a PN junction of compound semiconductors that emit light upon receiving a current. Unlike other light sources which use a filament, a light emitting diode does not have the problem of a short circuit caused by oxidization or heating. Also, the light emitting diode is an environmentally friendly device that has a long lifespan and is driven with low power consumption. In addition, the light emitting diode has a high response speed of simultaneously responding to an applied current, has excellent durability against temperature and shocks, and is manufactured in a single-operation semiconductor manufacturing process, and thus may be easily made compact and integrated.
With the commercialization of blue light emitting diodes, natural colors can be realized, and thus a light emitting diode is widely used not only in simple display devices that have been used in the past but also in backlight units (BLU) of mobile phones, flat panel displays, outdoor electric signs, gauge boards for cars, taillights, traffic signals, lightscape lights, etc., and also in the environment field or biotechnology in which water pollution or oxygen density in blood is measured. Furthermore, due to improved product performance and reduced manufacturing costs, the application fields of light emitting diodes has gradually extended, and thus the light emitting diodes are also used as an alternative illumination for home fluorescent lamps.
Recently, as electrophotographic image forming apparatuses have high speed and high image quality, a line printer head (LPH) that uses a light emitting diode as a light source in order to overcome the limits of a laser scanning unit (LSU) which is a conventional exposure apparatus has been developed. The LPH includes thousands of light emitting diodes arranged at intervals of several tens of μm, and each of the light emitting diodes changes light energy according to printing image data to transmit the printing image data to a photosensitive body that is disposed at a distance of several mm away from the light emitting diodes. In a conventional LPH, an optical system, which prevents lights emitted from adjacent light emitting diodes from overlapping, is further included.